Methods were developed for the estimation of 1-gamma-acetylmethadol, and related congeners or metabolites, i.e., 1-gamma-acetylbisnormethadol, 1-gamma-methadol, 1-gamma-normethadol, 1-gamma-acetylnormethadol, from biological materials. These techniques included extraction, ITLC and liquid scintillation estimation of radioactivity and were sensitive to 2-5 ng. Following a 2 milligram/kg s.c. injection of H3-LAAM in monkeys, the mean excretion of free drug after three weeks was 4.33% in urine, 20.23% in feces. Total radioactivity in urine was 20.60% and 36.34% in feces for the same time period. After oral administration of the same dose (2 milligram/kg) 2.34% of free LAAM was observed in urine, 19.47% in feces. Total radioactivity in urine was 17.66% and in feces, 27.37%. Mean peak plasma level after s.c. administration was 177 ng/ml at 1 hour; after oral administration the peak was at 4 hours--73 ng/ml. The half-life for s.c. and oral administration in plasma was 9.0 hours and 26 hours, respectively. The metabolites of LAAM identified in urine after exhaustive treatment using resin column solvents and ITLC scanning were: acetylnormethadol (major), methadol conjugate, normethadol conjugate, acetylbisnormethadol (trace). Unknowns I and II--the first being highly polar (hydroxyl groups) and the second appears to be acetylated on the nitrogen.